Field of the Invention
The present invention relates generally to communication networks. More specifically, the present invention relates to a method and apparatus for handling in-band signaling messages in radio access networks.
Description of the Related Art
In radio access networks such as evolved universal terrestrial radio access networks (E-UTRAN), datagrams such as packets or PDU's are often transmitted between network devices using various types of compression technology. Compressing aspects of the datagram such as headers and payload can improve overall system performance. In some configurations, various protocols can be used to compress and decompress aspects of the datagram. One such protocol is known as Packet Data Convergence Protocol (PDCP). Certain standards and proposed standards (for example, IETF RFC3095) require various protocols and various functionalities in order to properly operate among various devices. One such protocol is a robust header compression protocol, which is sometimes referred to as the ROHC protocol. This protocol supports a number of operation modes, including a uni-directional mode (U-mode), Bi-directional optimistic mode (O-mode), and Bi-directional reliable mode (R-mode).
In many communication protocols, various feedback systems have been implemented in order to ensure appropriate communication. For example, in ROHC, an ACK signaling acknowledges successful decompression of a packet on the decompression side of the communication. Successful decompression is defined as the context of the packet being up-to-date with a high probability. A NACK signal indicates that the dynamic context of the decompressor is out of synchronization. A NACK signal is generated when several successive packets have failed to be decompressed properly. A Static-NACK signal indicates that the static context of the decompression is not valid, or has not been established. Other in-band control signaling can also be used in the context of a packet data convergence protocol.